Walkthroughs
and GuidesOutside link to all
the information you'll need on this game, and more!Courtesy of: Gamefaqs.com

HOW
TO UNLOCK THE CLASSIC ASTEROIDS GAMEFollow the steps
below..
1. When you see 'Press Start' flashing on the Title screen hold Select and
press:
Circle Circle Circle, Triangle Square Square Circle
2. You will hear a sound to confirm that you have entered the code
correctly.